ClickUpdate

        string Current;
        private void ClickUpdate(string Old, string Next)
        {
            Color Transparent = Color.Transparent;
            Color Green = Color.Green;
            switch(Old)
            {
                case "game1":
                      game1.BackColor = Transparent;
                      break;
                case "game2":
                      game2.BackColor = Transparent;
                      break;
                case "game3":
                      game3.BackColor = Transparent;
                      break;
                case "game4":
                      game4.BackColor = Transparent;
                      break;
            }
            switch (Next)
            {
                case "game1":
                    game1.BackColor = Green;
                    break;
                case "game2":
                    game2.BackColor = Green;
                    break;
                case "game3":
                    game3.BackColor = Green;
                    break;
                case "game4":
                    game4.BackColor = Green;
                    break;
            }

        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Current = "game1";
            ClickUpdate(Current, "game1");

        }

        private void game1_Click(object sender, EventArgs e)
        {
            Current = "game1";
            ClickUpdate(Current, "game1");
        }

        private void game2_Click(object sender, EventArgs e)
        {
            Current = "game2";
            ClickUpdate(Current, "game2");
        }

        private void game3_Click(object sender, EventArgs e)
        {
            Current = "game3";
            ClickUpdate(Current, "game3");
        }

        private void game4_Click(object sender, EventArgs e)
        {
            Current = "game4";
            ClickUpdate(Current, "game4");
        }